[Avodah] Electricity

[D&E-H Bannett]

Re: << likely only turning on incandescent bulbs is a 
malacha de'oraisa becase of heating the filament to a very 
high temperature which is "aish">>

Every fluorescent has electrodes that become white hot 
because of electron or ion bombardment.  Many also have 
preheating to a reddish glow before the tube lights up.  The 
high temperature of the electrodes is required for the lamp 
to operate.

An incandescent bulb has one filament that is considered 
eish.  The fluorescent has two such sources of eish.  In a 
case where a person had to light a lamp on Shabbat for 
pikuach nefesh reasons, the psak of Rabbi Levi Yitzhak 
Halperin, the head of the Institute for Science and Halakha 
in Jerusalem was to light the incandescent.

The light from the fluorescent coating of the tube is 
"cold".


David